JP2004142451A - Method and apparatus of forming tire cord reinforcing layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of forming a tire cord reinforcing layer which can flexibly support production in small lots and manufacture a tire with a high uniformity level, and an apparatus for forming the cord reinforcing layer to be used in the method. <P>SOLUTION: Cords with rubber of a predetermined length coated with rubber in advance are stuck circumferentially onto a tire molding drum one by one. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a method for forming a cord reinforcing layer for a tire constituting a carcass or a belt of a tire and a cord reinforcing layer forming apparatus used for the method, and is particularly suitable for producing a small lot-sized tire, and moreover, a uniformity The present invention relates to a method for forming a tire cord reinforcing layer capable of improving the level and a cord reinforcing layer forming apparatus therefor.

方法 A conventional method of forming a cord reinforcing layer constituting a carcass or a belt of a tire is as follows. That is, first, a cord woven in an interdigitated form is passed between calendar rolls at a high speed, rubber is coated on both sides of the cord, and the cord is wound on a large-winding anti-reel and temporarily stored as an intermediate stock. Thereafter, the reel is unwound from the large-winding anti-reel, cut into small pieces each having a predetermined length D with a bias cutter, and the small pieces are joined in a direction intersecting the direction of the cord to form a continuous sheet having a width D. This is wound up on a small anti-reel and stored as an intermediate stock. Then, when molding a tire of the required size with the required molding machine, take out the small reel counter reel corresponding to this size from the intermediate stock, set it on the molding machine, then feed out a continuous sheet from the small reel counter reel and By repeating the operation of winding the tire around the forming drum and cutting it into the length of one tire, the cord reinforcing layer of the tire to be continuously formed can be sequentially formed.

However, the conventional method is efficient for mass-producing tires of the same size, but in a small-lot production system capable of responding to diversifying consumer needs, tires of small lots are frequently used. In the above-mentioned method, the intermediate stock of large rolls and small rolls is enormous, and the equipment such as the bias cutter is used for mass production. Switching requires a great deal of time, and the smaller the lot, the more wasteful the size switching time becomes.

い く つ か Several proposals have already been made to address this issue. One proposal is to apply and cut a long ribbon strip coated with rubber to a certain number of cords directly on a molding drum, and arrange the cut strips in the circumferential direction of the molding drum without gaps to form a cord reinforcing layer. (See, for example, Patent Document 1). In the case of a carcass cord reinforcing material for a radial tire, for example, since the extending direction of the cord is parallel to the axis of the forming drum, a ribbon strip is provided for each length corresponding to the total width of the cord reinforcing layer on the forming drum. The cord reinforcing layer can be formed by cutting and sticking the cut pieces on the forming drum by the number obtained by dividing the circumferential length of the forming drum by the ribbon strip width w. This method can be realized by setting the relationship between the circumferential length of the forming drum and the width of the ribbon strip so that the circumferential lengths of the forming drums of various sizes are all integral multiples of the width w of the ribbon strip. it can.

This method can cope with the production of tires of various sizes with one type of ribbon strip width w, and can reduce intermediate stock because there is no need to prepare ribbon strips of various types, and furthermore, the cutting length can be reduced. By simply changing the width, it is possible to correspond to the total width of the various cord reinforcing layers, and it does not take time to change the size, so that the problem of the conventional method can be solved, but if the precision of the ribbon width is not good. On the circumference of the forming drum, a joining portion occurs in which a ribbon piece and a ribbon piece that are adjacent to each other in the circumferential direction produce a gap therebetween or overlap each other. In order to prevent this, if all the ribbons on the circumference of the forming drum are joined together with a minute overlapped portion, an RFV (radial force variation) component of an order corresponding to the number of ribbon pieces corresponding to the overlapped portion is formed. There is a problem that it occurs and lowers the level of uniformity.

As another proposal, a case of a cord reinforcing material for a carcass of a radial tire will be described as an example.A long ribbon strip in which a certain number of cords are covered with rubber is spirally formed on a dedicated drum for forming a cord reinforcing layer. After winding to form a band, the band is cut along the axial direction of the dedicated drum and cut open, and then the cut piece is wound around a forming drum to form a cord reinforcing layer. One piece is wound so that the circumferential direction on the dedicated drum corresponds to the axial direction on the forming drum (for example, see Patent Document 2).

This method is also an improvement over the conventional method in that the intermediate stock can be reduced because it is possible to cope with the production of tires of various sizes with the width of one type of ribbon. Will correspond to the total width of the cord reinforcement layer on the forming drum, so the number of special drums will be at least as many as the total width of the cord reinforcement layer, and the cost and space for that will be enormous. Will be.

Furthermore, when winding the cut open piece around the forming drum, it is difficult to join the front and rear ends of the piece in the circumferential direction on the forming drum without gaps and without overlapping due to the expansion and contraction of the winding piece, There is also a problem that the connecting portion becomes a non-uniform portion and lowers the level of uniformity.
JP 2001-328180 A International Publication WO 01/17760 pamphlet

The present invention has been made in view of such a problem, and is capable of flexibly coping with small-lot production, and capable of producing a tire having a high uniformity level. It is an object of the present invention to provide a method of forming a cord and a device for forming a cord reinforcing layer therefor.

In the method for forming a tire cord reinforcing layer according to the first aspect of the present invention, a rubber-coated cord having a predetermined length, which is previously coated with rubber, is attached one by one on a tire building drum in parallel or inclined with the axis of the building drum. Things.

The method for forming a tire cord reinforcing layer according to claim 2 is the method according to claim 1, wherein when attaching the rubber cord to a molding drum, the rubber cord is attached to a radially inner layer in a radial direction. After laminating two layers with the outer layer, the rubberized cord of the outer layer is press-fitted between the rubberized cords of the inner layer.

The cord reinforcing layer forming apparatus according to claim 3 is a cord reinforcing layer forming apparatus used in the method for forming a tire cord reinforcing layer according to claim 1 or 2.
A cord pasting and cutting machine that pastes rubber cords one by one on a molding drum and cuts a continuous rubber cord into the predetermined length, a relay drum that feeds out a cord from a cord reel and sends it to a cord pasting and cutting machine, a cord. A rubber coating machine for continuously coating rubber on the cord between the reel and the relay drum, and a festoon for adjusting excess or deficiency of the rubberized cord generated between the cord attaching / cutting machine and the relay drum. Things.

According to the first aspect of the present invention, since the cords with rubber are adhered one by one on the forming drum, an intermediate for a large roll or a small roll is required as in the conventional method of forming a tire cord reinforcing layer. Inventories are no longer required, and different tire sizes can be accommodated only by changing the cutting length of the rubberized cord on the molding drum, so there is no reduction in productivity due to size switching, and Since the cord with rubber can be uniformly arranged on the circumference of the molding drum, the uniformity level can be improved.

According to the second aspect of the present invention, since the rubberized cord of the outer layer is press-fitted between the rubberized cords of the inner layer, the circumferential gap between the cords can be reduced.

According to the third aspect of the present invention, with the above-described configuration, the method for forming a tire cord reinforcing layer according to the first or second aspect can be easily realized, and a predetermined length of rubber is provided after the cord is fed. The process of pasting the cord onto the forming drum can be performed continuously, and the space for intermediate stock can be further reduced.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic perspective view showing a configuration of a cord reinforcement layer forming apparatus 1 for forming a cord reinforcement layer of a carcass of a radial tire, and FIG. 2 is a schematic side view showing a line II-II in FIG. It is. The cord reinforcing layer forming apparatus 1 includes a cord sticking and cutting machine 3 for sticking cords G with rubber one by one on a forming drum 2 for forming a carcass band and cutting a continuous cord G with rubber into a predetermined length l. A reel stand 5 for rotatably supporting the code reel 4; a relay drum 6 for feeding out a cord U not covered with rubber from the code reel 4 and continuously sending the cord U to the cord sticking and cutting machine 3; a cord reel 4 and a relay drum 6, a rubber coating machine 7 for continuously coating rubber on the cord U, and a cord with rubber generated between the intermittently operating cord sticking and cutting machine 3 and the continuously operating relay drum 6. It has a festoon 8 for adjusting the excess or deficiency of G.

The cord attaching / cutting machine 3 includes a cutter 12 for cutting the cord G with rubber, a pressing roller 13 for pushing the cord G with rubber against the molding drum, and a movable base 11 on which these are mounted and reciprocates in parallel with the axis of the molding drum 2. The cutter 12 and the pressing roller 13 are attached to the movable base 11 in a state where the cutter 12 and the pressing roller 13 can be separated from and approached to the molding drum 2.

Further, the rubber coating machine 7 has an insulation head 15 having a through-hole through which the cord passes, and continuously covering the cord with the rubber in the through-hole, and continuously applying the coating rubber from a direction orthogonal to the through-hole. And a rubber extruder 16 for feeding.

Next, a method for forming a carcass cord reinforcing layer using the cord reinforcing layer forming apparatus 1 configured as described above will be described. FIG. 1 shows that the inner liner N is already affixed to the forming drum 2 and a plurality of cords G with rubber cut to a predetermined length 1 are arranged at a predetermined pitch on a part of the circumference thereof on the circumference thereof. On the other hand, the cord sticking and cutting machine 3 shows a state in which the moving base 11 is positioned at the right end of the molding drum 2 and the cutter 12 and the pressing roller 13 are kept separated from the molding drum 2.

After the state shown in FIG. 1, the forming drum 2 is rotated by a small angle corresponding to the circumferential sticking pitch of the cord G with rubber, and the moving base 11 of the cord sticking and cutting machine 3 is moved parallel to the axis of the forming drum 2. To the left end along the direction X. At this time, the cord G with rubber held by the pressing roller 13 of the cord pasting and cutting machine 3 also moves to the left together with the pressing roller 13, so that the weight 14 of the festoon 8 rises, and the amount of cord storage in the festoon 8 decreases. I do.

Next, the pressing roller 13 holding the tip of the rubber-attached cord G is made to approach the forming drum 2, and the tip of the rubber-attached cord G is pressed onto the inner liner N and stuck.
When the moving base 11 is displaced to the right at a constant speed while the pressing roller 13 is pressed against the molding drum 2, the cord G with rubber is sequentially moved from left to right by the rolling of the pressing roller 13. It is attached while being pressed by N. Then, when the moving base is located at the left end in FIG. 1, the cutter 12 is lowered to cut the rubber cord G. In this manner, the rubber cord G having the length 1 can be arranged on the molding drum 2. Thereafter, the cutter 12 and the pressing roller 13 are separated from the forming drum 2 while the tip of the rubber-attached cord G that has been cut and left on the side of the code sticking and cutting machine 3 is held by the pressing roller 13. Then, the process returns to the step of rotating the forming drum 2 by a small angle at the pitch.

The supply of the rubber cord G to the festoon 8 is performed by the relay drum 6, and the relay drum 6 is configured to wind the rubber cord G and discharge the wound rubber cord G at the same time. Then, the released rubberized cord G is pulled in by the weight 14 of the festoon 8 and stored in the festoon 8. Since the cord of the rubber cord G wound around the relay drum 6 is directly connected to the cord reel 4, the cord U is fed out of the cord reel 4 by winding the relay drum 6, but the cord U is unwound from the cord reel 4. After being fed out, it passes through a through hole provided in the insulation head 15 of the rubber coating machine 7, and at this time, the rubber supplied from the rubber extruder 16 is coated around the cord U.

In the method of forming the cord reinforcing layer described above with reference to FIG. 1, the rubber cord G having a predetermined length l is cut by cutting the rear end of the rubber cord G on the molding drum 2. Alternatively, before attaching the cord G with rubber to the molding drum 2, the cord G with rubber may be cut into a length l, and then the cut cord may be attached to the molding drum. .

FIG. 3 is a schematic side view showing a modification of the present embodiment and corresponding to an arrow II-II in FIG. 1. As shown in FIG. 3A, in order to reduce the pitch of the rubber cords G on the molding drum 2, the rubber cords G cut to a predetermined length 1 The circumferential pitch of the rubber-attached cords G in each layer is a pitch in which a slight gap d is provided between cords G adjacent to each other in the circumferential direction. Then, by moving the press-fit cylinder 23 along the outer periphery of the forming drum while pressing the press-fit roller 24 with the press-fit cylinder 23, as shown in FIG. The one-layer cord in which the rubber-attached cord G can be pressed into the gap between the cords G in the inner layer in the radial direction, and the pitch of the rubber-attached cord G in the circumferential direction is half of the pitch when two cords are arranged A reinforcing layer can be formed.

As described above, the embodiment of the present invention has been described by taking the cord reinforcing layer constituting the radial carcass as an example.However, the present invention is not limited to the case where the cord extending direction of the cord reinforcing layer on the forming drum is not orthogonal to the forming drum axis. For example, as shown in a schematic perspective view of a forming drum 22 for forming a belt tread band in FIG. 4, the present invention is applicable to a cord reinforcing layer constituting a belt for a radial tire. Can be. In this case, since the extending direction of the rubber-attached cord V is inclined with respect to the axis of the molding drum 22, the cutter 32 and the pressing roller 33 are formed in an arc shape to dispose the cord V on the periphery of the molding drum 22. In other respects, it is necessary to move, but in the same manner as the formation of the carcass cord reinforcing layer, it can be performed.

As is clear from the above description, according to the present invention, a rubber-coated cord of a predetermined length, which is previously coated with rubber, is pasted one by one on a tire building drum, so that it can flexibly cope with small lot production. In addition, it is possible to manufacture a tire having a high uniformity level.

1 is a schematic perspective view illustrating a configuration of a cord reinforcing layer forming apparatus according to an embodiment of the present invention. FIG. 2 is a schematic side view showing a modification of the present embodiment, as viewed in the direction of arrows II-II in FIG. 1. FIG. 2 is a schematic side view corresponding to an arrow II-II in FIG. 1. FIG. 4 is a schematic perspective view of a molding drum showing a method of forming a belt cord reinforcing layer on a molding drum for belt tread band molding.

Explanation of reference numerals

1 Cord Reinforcement Layer Forming Apparatus 2 Forming Drum 3 Cord Pasting and Cutting Machine 4 Code Reel 5 Reel Stand 6 Relay Drum 7 Rubber Coating Machine 8 Festoon 11 Movable Base 12 Cutter 13 Press Roller 14 Weight 15 Insulation Head 16 Rubber Extruder 22 Rubber Drum 23 Press-in cylinder 24 Press-in roller 32 Cutter 33 Press roller N Inner liner G, V Cord with rubber U code

Claims (3)

(4) A method for forming a tire cord reinforcing layer in which a rubber-coated cord of a predetermined length, which is previously coated with rubber, is attached one by one on a tire building drum in parallel or inclined with the axis of the building drum. When sticking the rubberized cord on the forming drum, after laminating the rubberized cord into two layers of a radially inner layer and a radially outer layer, the rubberized cord of the outer layer is rubberized on the inner layer. The method for forming a tire cord reinforcing layer according to claim 1, wherein the cord is press-fitted between the attached cords. A cord reinforcing layer forming apparatus used in the method for forming a tire cord reinforcing layer according to claim 1 or 2,
A cord pasting and cutting machine that pastes rubber cords one by one on a molding drum and cuts a continuous rubber cord into the predetermined length, a relay drum that feeds out a cord from a cord reel and sends it to a cord pasting and cutting machine, a cord. A rubber coating machine for continuously coating rubber on the cord between the reel and the relay drum, and a festoon for adjusting excess or deficiency of the rubberized cord generated between the cord attaching / cutting machine and the relay drum. Cord reinforcement layer forming device.

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